palaeoproductivity in the ross sea antarctica during the last 15 kyr bp and its link with ice core temperature proxies

AbstractA detailed study of organic carbon content obtained from two sediment cores collected in the Joides basin, western Ross Sea, Antarctica, was carried out. The variations observed during the last deglaciation and the Holocene were compared to the high-resolution climatic records (EPICA DC and Taylor Dome) preserved in the ice. The importance of the carbon content as a proxy for palaeoclimatic and palaeoenvironmental changes was investigated. A dramatic decrease in the Ross Sea palaeoproductivity was observed during the Antarctic Cold Reversal (12.5–14 kyr BP). Another decrease in total organic carbon in the second half of the Holocene (after 5–6 kyr BP) confirms the climate worsening observed in previous studies

Palaeoproductivity in the Ross Sea, Antarctica, during the last 15 kyr BP and its link with ice-core temperature proxies

ABSTRACT. A detailed study of organic carbon content obtained from two sediment cores collected in the Joides basin, western Ross Sea, Antarctica, was carried out. The variations observed during the last deglaciation and the Holocene were compared to the high-resolution climatic records (EPICA DC and Taylor Dome) preserved in the ice. The importance of the carbon content as a proxy for palaeoclimatic and palaeoenvironmental changes was investigated. A dramatic decrease in the Ross Sea palaeoproductivity was observed during the Antarctic Cold Reversal (12.5\u201314 kyr BP). In the second half of the Holocene (after 5\u20136 kyr BP) another decrease in total organic carbon confirms the climate worsening observed in previous studies

Role of the River Soča in transfering mercury compounds into the gulf of Trieste

In presented work different mercury forms in inflow of River So~a at mixing zone between fresh and sea water have been investigated. Regarding to River So~a water regime three sampling periods have been proposed at nine sampling locations.Total Hg concentrations were between 4.5 and 174 ng/l with average value of 25.9 ng/l. Most Hg (72%) was bounded to suspended matter. The highest values in water column were measured in May when the average total Hg concentration was 33.6 ng/l. Methylmercury(MeHg) concentrations were in wide range between 12.0 and 1350 pg/l (average 175 pg/l). Most MeHg was in dissolved form (85%). Dissolved Hg (DGM) concentration in water was between 0.03 to 2.6 ng/l. More than ten years after closure of the mercury mine in Idrija concentrations of different Hg species in River Soča remains very high

First-trimester prenatal screening for the common 35delG GJB2 mutation causing prelingual deafness

Objective This study evaluates the prevalence of 35delG GJB2 mutation, the most common genetic mutation causing prelingual deafness, and its screening feasibility and acceptability in pregnant women undergoing first-trimester CVS for chromosomal abnormality investigation. Methods Samples were taken from 5786 pregnant women who requested CVS for chromosomal analysis. The Samples were split into two aliquots for chromosome and DNA analysis, respectively. The results of foetal karyotyping were provided 7 days after sampling, at which time the fully informed couple decided whether or not to undergo DNA testing. Results Of the 5449 eligible candidates, 2997 (55.0%) chose to undergo 35delG testing. Among them, 67 proved to be carriers of the mutation, resulting in a prevalence rate of 1 : 44.7 (2.23%). There were no homozygous foetuses, but two double heterozygous foetuses were found, and in one case the couple chose to terminate the pregnancy. Conclusions The results confirm the high frequency of 35delG mutation in the Italian population. The study shows that prenatal screening for GJB2 mutations in pregnant women with no retrospective risk for deafness appears to be feasible and highly acceptable. Consequently, given evidence that early evaluation and treatment significantly improve speech and language skills, as well as social and emotional well-being in affected children, 35delG mutation analysis in pregnant women booking CVS primarily for chromosomal investigation could be considered a useful addition to more comprehensive population screening strategies. Copyrigh

Grain Size, Mineralogy and Geochemistry in Late Quaternary Sediments from the Western Ross Sea outer Slope as Proxies for Climate Changes Antarctica

Textural, mineralogical and geochemical investigations of three sedimentary sequences from the Ross Sea continental slope allow to give some important indications on climatic and environmental changes occurred during the Late Quaternary. The cores show cyclical changes in several proxies (grain size, mineralogical and geochemical parameters) which are in phase with glacial/interglacial changes (MIS 1\u20138). Such fluctuations are supposed to be driven by changes in transport mechanisms, reworking and provenance of the material, as well as by changes in direction and strength of marine currents induced by variations in the ice coverage